You could do that if the bar will fit in the hole. You would have to take the moving clamp end (that slides on the bar) off and feed it though the hole and then slide the clamp end back on. Then you would have to get to it to clamp it.
This is what I use:

They go through the dog hole and then you tighten the allen screw to attach it tightly. These are by TSO. Of course, they require not only a hole in the base of the tool mount, but also holes in your workbench as well.
This one is holding my tabletop drill press on the bench. But I also have the same mount for a tabletop sander and a drill press that uses my Dremel tool.
Note, there are multiple sizes of dog holes and they have to match the bench dogs.
Here is a link where you can get them:
TSO Products
This is what I use:

They go through the dog hole and then you tighten the allen screw to attach it tightly. These are by TSO. Of course, they require not only a hole in the base of the tool mount, but also holes in your workbench as well.
Note, there are multiple sizes of dog holes and they have to match the bench dogs.
TSO Products




